From 5db19d426953b5c15672c80b4481ab6614746ec4 Mon Sep 17 00:00:00 2001
From: Peter Van der Beken <peterv@propagandism.org>
Date: Sun, 17 Mar 2013 21:47:12 -0400
Subject: [PATCH] Bug 812617 - Provide a JSBindingFinalized hook for the native
 classes using Web IDL bindings to know when their JS wrapper has been
 finalized; r=bzbarsky

--HG--
extra : rebase_source : bb5059a170f3c2f4aa977190fceea421b41b5e58
---
 dom/bindings/BindingUtils.h | 19 +++++++++++++++++++
 dom/bindings/Codegen.py     |  3 ++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/dom/bindings/BindingUtils.h b/dom/bindings/BindingUtils.h
index 7b2b4d5accc2..71fac771893b 100644
--- a/dom/bindings/BindingUtils.h
+++ b/dom/bindings/BindingUtils.h
@@ -1667,6 +1667,25 @@ bool
 NativeToString(JSContext* cx, JSObject* wrapper, JSObject* obj, const char* pre,
                const char* post, JS::Value* v);
 
+HAS_MEMBER(JSBindingFinalized)
+
+template<class T, bool hasCallback=HasJSBindingFinalizedMember<T>::Value>
+struct JSBindingFinalized
+{
+  static void Finalized(T* self)
+  {
+  }
+};
+
+template<class T>
+struct JSBindingFinalized<T, true>
+{
+  static void Finalized(T* self)
+  {
+    self->JSBindingFinalized();
+  }
+};
+
 nsresult
 ReparentWrapper(JSContext* aCx, JSObject* aObj);
 
diff --git a/dom/bindings/Codegen.py b/dom/bindings/Codegen.py
index 5650f3abd658..35d52f8523d9 100644
--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -919,7 +919,8 @@ def finalizeHook(descriptor, hookName, context):
     if descriptor.customFinalize:
         finalize = "self->%s(%s);" % (hookName, context)
     else:
-        finalize = "ClearWrapper(self, self);\n" if descriptor.wrapperCache else ""
+        finalize = "JSBindingFinalized<%s>::Finalized(self);\n" % descriptor.nativeType
+        finalize += "ClearWrapper(self, self);\n" if descriptor.wrapperCache else ""
         if descriptor.workers:
             finalize += "self->Release();"
         elif descriptor.nativeOwnership == 'nsisupports':